Internet voting systems are inherently insecure and should not be allowed in the upcoming general elections, a noted security researcher said at the RSA Conference 2012 being held here this week.

David Jefferson, a computer scientist at Lawrence Livermore National Laboratories and chairman of the election watchdog group Verified Voting, called on election officials around the country to drop plans to allow an estimated 3.5 million voters to cast their ballots over the Internet in this year's general elections.

In an interview with Computerworld on Wednesday, Jefferson warned that the systems that enable such voting are far too insecure to be trusted and should be jettisoned altogether.

Jefferson is scheduled to participate in a panel discussion on the topic at RSA on Thursday. Also on the panel are noted cryptographer and security guru Ron Rivest, who is the "R" in RSA, and Alex Halderman, an academic whose research on security vulnerabilities in e-voting systems prompted elections officials in Washington to drop plans to use an e-voting system in 2010.

"There's a wave of interest across the country, mostly among election officials and one agency of the [Department of Defense] to offer Internet voting," to overseas citizens and members of the military, Jefferson said. "From a security point of view, it is an insane thing to do."

A total of 33 states allow citizens to use the Internet to cast their ballots. In a majority of cases, those eligible to vote over the Internet receive their blank ballots over the Web, fill them in and submit their ballots via email as a PDF attachment. Some states, such as Arizona, have begun piloting projects that allow eligible voters to log into a web portal, authenticate themselves and submit their ballots via the portal.

The insecurity and the inability to audit such voting practices is unacceptable, Jefferson said.

Ballots sent via email for instance, are transmitted in the clear without encryption. That means any entity, such as an ISP or a malicious hacker that sits between the voter and the county where the vote is being cast, can view, filter, substitute or modify the ballot, he said.

Meanwhile, the e-voting Web portals that have been proposed for use in Arizona and are being tested in other states, are prone to all the security vulnerabilities and attacks that other sites face, he said.

As one example, he pointed to an attack crafted by Halderman , an assistant professor of computer science at the University of Michigan, in 2010 against a Digital Vote by Mail System that was proposed for use in Washington. The system was designed to be used by overseas voters and military personnel based in other countries.

But Halderman, along with a team of researchers, easily broke into the system, and showed how they could modify and replace marked ballots in the system. The researchers even tweaked the system so that voters would be greeted with the University of Michigan fight song when they landed on the vote confirmation page.

The election officials in charge of such systems do not have the technical expertise or the resources needed to detect or protect their systems against such attacks, Jefferson said. "The kind of attack that Halderman did can be repeated any where at any time," with little response, he said.

In addition, Web-based voting systems are vulnerable to the same security threats that face other websites. These threats include DNS routing attacks, man-in-the middle attacks and denial-of-service attacks and can prevent voters from casting their ballots. The client systems that eligible voters use to cast their ballots are equally vulnerable, Jefferson said. Numerous attacks are possible where a voter might case a ballot and have no way of knowing whether the ballot was intercepted, modified or cast at all.

Electronic voting systems of the sort proposed for use in this year's general elections do not provide anywhere near the auditability provided by paper votes, he said. While there are mechanisms to ensure that the same voter does not cast multiple ballots, there is nothing to prove that a ballot was cast in the manner that the voter intended, he said.

"Once you put ink on paper, you can't change it without that change being easily detectable," Jefferson said. "Paper is indelible. People can see it, track it and read it." He noted that the only country with an Internet voting system comparable to the U.S. is Estonia. Other countries have tried e-voting technology and have either gone back to paper voting or are reconsidering it, he said.

"What we are asking every state, every jurisdiction to do is not use Internet voting," Jefferson said. "It is OK to transmit blank ballots over the Internet" to overseas and absentee voters he said, but not ballots that have been filled in.

Susannah Goodman, director of the election reform project at the watchdog group Common Cause, said states that are moving ahead with Internet voting plans would do well to look at states such as New York and California which have said they will not adopt such measures,because of security concerns.

"Knowing what we know, it is not a verifiable form of voting. It is not a safe form of voting," she said.